This invention relates to heat exchanger tube cleaning and is an improvement over certain concepts disclosed in co-pending U.S patent application Ser. No. 920,644, filed July 3, 1978, now U.S. Pat. No. 4,269,264, granted May 26, 1981, by Richard W. Goeldner, entitled "Cleaning Of Heat Exchanger Tubing", and assigned to a common assignee.
In the said co-pending application, a large plurality of condenser cooling tubes are formed into bundles at one end of the condenser by flow confinement plates or spacers which are secured to the usual tube plates or tube sheets. Basket assemblies containing tube cleaning brushes or the like are mounted at the ends of the tubes. A distributor arm assembly is disposed adjacent the compartmentalized tubes and basket assemblies and is actuatable to sweep across the tube ends, sealing each compartment in succession as it moves. Means are provided to cause a counter-flow of cooling water to flow from the arm assembly and through one bundle of tubes at a time to cause the cleaning brushes to move through the tubes. After the arm assembly passes by a particular bundle, the fluid counter-flow ceases and the brushes return through the tubes to their respective basket assemblies.
It is important that the tubes be compartmentalized or formed into bundles at their ends in order to provide adequate pressure for the fluid counter-flow. Thus, the use of the said flow confinement plates.
In some instances, it may be desirable to convert an existing installation wherein there is no counter-flow system and distributor arm into one which utilizes such concepts. This requires the compartmentalizing of the tube ends. It has been found that in some prior installations, the tubes and their basket assemblies are disposed so close together that the installation of the confinement plates or spacers therebetween is extremely difficult and costly, or may be virtually impossible.
Furthermore, and for efficiency purposes, it is often desirable to utilize as many cooling tubes as possible within a given size condenser. The use of tube confinement plates between the basket assemblies may therefore be undesirable, even in new installations.
It is a task of the present invention to provide a distributor arm counter-flow system which eliminates the need for flow confinement plates or spacers which are disposed between the basket assemblies.
It is a further task of the invention to simplify the installation of a distributor arm counter-flow system in a previous installation not utilizing these concepts.
It is yet another task of the invention to assist in the utilization of as many tubes as possible in a condenser of given size.
In accordance with one aspect of the invention, the compartmentalization of the tubes for fluid counter-flow is accomplished, not by spacers between the basket assemblies, but by the basket assemblies themsevles.
In accordance with another aspect of the invention, each basket of the assemblies arrayed to form the boundaries of a desired compartment is formed with an outwardly extending lip, with the lips of adjacent baskets joined to form an elongated contact surface for sealing engagement with the distributor arm.
In accordance with yet another aspect of the invention, the lips of the adjacent baskets forming the respective compartments are generally arcuate, and the distributor arm portions adapted to engage the elongated contact surface are at least as wide as the arcuate extent of each basket lip. The radius of the lip arc is greater than that of the basket.
In accordance with a further aspect of the invention, each basket lip forms the outer end of a closed partition forming an arcuate basket side wall which extends toward the inner basket end and serves to support the basket longitudinally against any pressure exerted by the distributor arm when sealing contact is made with the lips.
In accordance with additional aspects of the invention, the partitions of adjacent baskets are joined to provide a seal against radial passage of liquid therethrough and the inner partition ends form stops for engagement with the adjacent tube sheets.